Q. What uses the most battery power on my laptop?

A. The LCD display. In fact, almost half the power in most laptops is used by the screen, which is why dimming your screen can save you a lot of battery life. Below is a list of the major power consumers on your laptop. This list also applies to desktop computers, other than the screen figure.

LCD: 43%

Chipset: 21%

Processor: 9%

Graphics: 8%

Hard Drive: 5%

Network: 4%

Other bits: 10%

Obviously different systems will vary based on their components, but this gives a rough idea of where that battery power goes.

Discuss this Article 1

We had a reader ask about this article:
The question posed in the subject line was addressed in the Windows Tips & Tricks eLetter for April 6, 2009. This is great information but I have a question. I've heard that wireless networking "eats" battery life like crazy. That is why most current laptops have a way of shutting down the radio when not in use. Is this true? Is that factored into the "network" result of 4%? I would expect this result to be much higher if wireless networking is truly an issue.
Here's John's response:
Interesting question. After some additional research it seems that most modern wireless networks/bluetooth are not the huge battery killers we typically think they are compared to something like a large laptop screen. The 4% includes wireless/bluetooth. Yes, its great to turn them off if you are not using them but consider the average mobile phone and its tiny battery. Those devices have wlan/Bluetooth and can run for a day. Now consider the battery we have in a laptop and the proportion of battery used by the wlan/bluetooth is pretty small compared to everything else. Turning off is also good from a security perspective to not have networks available that you are not using.